Evaluate the Influence of extract and powder of tarragon on the growthperformance of broiler chickens

In order to investigate the effects of the Tarragon byproducts on the growth performance, carcass traits, cellular and humoral immunoresponse of broilers, one-day- old one hundred sixty-eight Ross 308 chicks were randomly allocated in to four treatment groups in 24cages (6 replicates per treatment) and 7 chicks per replicate. The treatments were included: 1) basal diet (control), 2) basal diet + 500 μl/lit Hydro alcoholic extract of tarragon in drinking water, 3) basal diet + 1% dietary tarragon powder and 4) basal diet + 1% dietary tarragon powder + 500 μl/lit of tarragon extract in drinking water. Results indicated that at the starter, grower, finisher and total periods of time, the birds that were recived 1% dietary tarragon powder had a better growth performance rather than other birds, so that, feed intake and weight gain were significantly increased (P ≤ 0.05) and feed conversion ratio was improved. In these birds, the relative weights of carcass and bursaof Fabresious was also greater than other birds (P ≤ 0.05). No significant differences were observed in the cellular immunity response (change in foot membrane thickness in response to Phytohemagglutinin injection) and humoral imiunity response (antibody response toNewcastle virus and antibody response to injected SRBC) due to treatments. Based on the results, the use of one percent tarragon powder in the diet of broilers is recommended to improve the growth efficiency and carcass yield.